Sharks are disappearing from the world’s oceans. The numbers of many large shark species have declined by more than half due to increased demand for shark fins and meat, recreational shark fisheries, as well as tuna and swordfish fisheries, where millions of sharks are taken by accident each year.

Now, the global status of large sharks has been assessed by the World Conservation Union, which is widely recognized as the most comprehensive, scientific-based information source on the threat status of plants and animals.

“As a result of high and mostly unrestricted fishing pressure, many sharks are now considered to be at risk of extinction,” explained Julia Baum, a member of the union’s Shark Specialist Group

“Of particular concern is the scalloped hammerhead shark, an iconic coastal species, which will be listed on the 2008 IUCN Red List as globally endangered due to overfishing and high demand for its valuable fins in the shark fin trade,” added Ms. Baum, who is a postdoctoral fellow at Scripps Institution of Oceanography.

Ms. Baum pointed out that fishing for sharks in international waters is unrestricted, and she supports a recently adopted United Nations resolution calling for immediate shark catch limits as well as a meaningful ban on shark finning, the practice of removing only a shark’s fins and dumping the still live but now helpless shark into the ocean to die.

Costa Rica is a major supplier to the international shark fin trade.

Research at Canada’s Dalhousie University over the past five years, conducted by Ms. Baum and the late Ransom Myers, demonstrated the magnitude of shark declines in the northwest Atlantic Ocean. All species the team looked at had declined by over 50 per cent since the early 1970s. For many large coastal shark species, the declines were much greater: tiger, scalloped hammerhead, bull and dusky shark populations have all plummeted by more than 95 per cent.

A commercial fish factory vessel was boarded this month by Costa Rican officials because they said it was involved in illegal fishing in the protected area of Isla del Coco. However, investigators had to let the 25-person crew go because there was uncertainty in the law regarding this kind of activity. The crew was seeking tuna but sharks, including hammerheads for which the waters around the island are famous are likely victims, too.

SAN JOSE, Costa Rica (Reuters) – Costa Rican President Oscar Arias has ordered the expropriation of lucrative beach-front land to protect the endangered leatherback sea turtle, the government said on Thursday.Arias began expropriation procedures for some 30 hectares (74 acres) of land in northwestern Costa Rica, the most important leatherback sea turtle nesting site on the Pacific Rim, Energy and Environment Minister Roberto Dobles said.”We are only complying with the law that established Las Baulas (national marine park) in 1995,” Dobles told Reuters.

Some of the expropriated land owners, mostly Europeans and U.S. citizens, had resisted the expropriation even though the land was made a national park by law in 1995.

Environmentalists hailed the move to protect the turtles, which have been declining in alarming numbers in recent years.

“It will help us to restore the population of leatherback turtles in the Pacific,” said Todd Steiner of the San Francisco-based Turtle Island Restoration Network.

Environmentalists say 95 percent of leatherbacks in the Pacific Ocean have vanished in the last 20 years due to human activity like fishing, poaching of their eggs and building near their nests.

Thousands of leatherbacks built nests at the Las Baulas beaches 10 years ago but the number has dropped to below 100 in the last five years.

Leatherbacks, which can reach a shell length of 5.6 feet and a weight of 1,543 pounds (700 kg), often die after being entangled in fishing lines and nets.